Internet Zone tab

Click the numbers to learn about specific controls, or read an introduction. To reach this tab: 1. Go to Firewall / Main tab 2. Under Internet Zone Security, click the Custom button.

Internet Zone tab

Use this dialog box to customize high security and medium security settings for traffic to and from the Internet Zone.

High security settings for the Internet Zone

These are the port and protocol restrictions applied to the Internet Zone when High security is selected in the Main tab of the Firewall panel.

Tip To view the settings for medium security, scroll down below the high security settings.

Default configuration

The default configuration for high security blocks all inbound and outbound traffic through ports not being used by programs you have given access or server permission except:

• DHCP broadcast/multicast
• Outgoing DHCP (port 67)*
• Outgoing DNS (port 53) **

Allowing Additional Ports

You can allow communication through additional ports at high security either by selecting one of the preconfigured protocols shown (ICMP, IGMP, and so forth), or by specifying ports. To specify a ports, follow these steps:

1. Scroll to the bottom of the high security list.
2. Click the port type desired: incoming UDP, outgoing UDP, incoming TCP, or outgoing TCP. A text box labeled Ports appears at the bottom of the dialog box.
3. Type the ports or port ranges you want to allow in the Ports text box, separated by commas.
   Example: 139, 200-300
4. Click Apply or OK.

*On Windows 9x systems
**If the machine is configured as an ICS gateway in the Security tab.

Medium security settings for the Internet Zone

These are the port and protocol restrictions applied to the Internet Zone when Medium security is selected in the Main tab of the Firewall panel.

Default configuration

The default settings for medium security allow inbound and outbound traffic through all ports except except incoming NetBIOS traffic (ports 135, 137-139, 445). The NetBIOS protocol enables file and printer sharing on local networks. It is blocked at medium security for the Internet Zone because, if exposed to the Internet, it is vulnerable to common intrusion attempts.

Blocking Additional Ports

You can block additional ports at medium security either by selecting one of the preconfigured protocols shown (ICMP, IGMP, and so forth), or by specifying ports. To specify ports, follow these steps:

1. Scroll to the bottom of the medium security list.
2. Click the port type desired: incoming UDP, outgoing UDP, incoming TCP, or outgoing TCP. A text box labeled Ports appears at the bottom of the dialog box.
3. Type the ports or port ranges you want to block in the Ports text box, separated by commas.
   Example: 139, 200-300
4. Click Apply or OK.

Related Topics

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Related Topics

Security levels

Glossary

Internet Zone
The Internet Zone contains all the computers in the world—except those you have added to the Trusted Zone or Blocked Zone.

ZoneAlarm Pro applies the strictest security to the Internet Zone, keeping you safe from hackers. Meanwhile, the medium security settings of the Trusted Zone enable you to communicate easily with the computers or networks you know and trust—for example, your home network PCs, or your business network.

DNS (Domain Name System)
A data query service generally used on the Internet for translating host names or domain names (like www.yoursite.com) into Internet addresses (like 123.456.789.0).

DHCP (Dynamic Host Configuration Protocol)
A protocol used to support dynamic IP addressing. Rather than giving you a static IP address, your ISP may assign a different IP address to you each time you log on. This allows the provider to serve a large number of customers with a relatively small number of IP addresses.

DHCP (Dynamic Host Configuration Protocol) broadcast/multicast
A type of message used by a client computer on a network that uses dynamic IP addressing. When the computer comes online, if it needs an IP address, it issues a broadcast message to any DHCP servers which are on the network. When a DHCP server receives the broadcast, it assigns an IP address to the computer.

NetBIOS (Network Basic Input/Output System)
A program that allows applications on different computers to communicate within a local network. By default, ZoneAlarm Pro allows NetBIOS traffic in the Trusted Zone, but blocks it in the Internet Zone. This enables file sharing on local networks, while protecting you from NetBIOS vulnerabilities on the Internet.